Yes, the likes of Arrows, Super Aguri, Midland, Spyker and even Prost were pretty bad, one or two of those were awful.
I only got into F1 a couple of years back, so it'd be harsh for me to vote for one of those teams, although I've been able to catch up on old races via certain means
So, I've voted for Toyota. Their expenditure over the seasons has vastly outweighed the performances they've given us, with their biggest success being this year, at Bahrain, where they locked out the front row, only to throw the race away with poor tactical nous and some odd decisions.
After that, their car development seemed to go backwards (or rather, they stood still while the rest went forwards), and they had another mediocre season.